fs/xfs/libxfs/xfs_dquot_buf.c

   1 /*
   2  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   3  * Copyright (c) 2013 Red Hat, Inc.
   4  * All Rights Reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it would be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write the Free Software Foundation,
  17  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19 #include "xfs.h"
  20 #include "xfs_fs.h"
  21 #include "xfs_shared.h"
  22 #include "xfs_format.h"
  23 #include "xfs_log_format.h"
  24 #include "xfs_trans_resv.h"
  25 #include "xfs_mount.h"
  26 #include "xfs_inode.h"
  27 #include "xfs_quota.h"
  28 #include "xfs_trans.h"
  29 #include "xfs_qm.h"
  30 #include "xfs_error.h"
  31 #include "xfs_cksum.h"
  32 #include "xfs_trace.h"
  33
  34 int
  35 xfs_calc_dquots_per_chunk(
  36         unsigned int            nbblks) /* basic block units */
  37 {
  38         ASSERT(nbblks > 0);
  39         return BBTOB(nbblks) / sizeof(xfs_dqblk_t);
  40 }
  41
  42 /*
  43  * Do some primitive error checking on ondisk dquot data structures.
  44  */
  45 xfs_failaddr_t
  46 xfs_dquot_verify(
  47         struct xfs_mount *mp,
  48         xfs_disk_dquot_t *ddq,
  49         xfs_dqid_t       id,
  50         uint             type,    /* used only when IO_dorepair is true */
  51         uint             flags)
  52 {
  53         /*
  54          * We can encounter an uninitialized dquot buffer for 2 reasons:
  55          * 1. If we crash while deleting the quotainode(s), and those blks got
  56          *    used for user data. This is because we take the path of regular
  57          *    file deletion; however, the size field of quotainodes is never
  58          *    updated, so all the tricks that we play in itruncate_finish
  59          *    don't quite matter.
  60          *
  61          * 2. We don't play the quota buffers when there's a quotaoff logitem.
  62          *    But the allocation will be replayed so we'll end up with an
  63          *    uninitialized quota block.
  64          *
  65          * This is all fine; things are still consistent, and we haven't lost
  66          * any quota information. Just don't complain about bad dquot blks.
  67          */
  68         if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC))
  69                 return __this_address;
  70         if (ddq->d_version != XFS_DQUOT_VERSION)
  71                 return __this_address;
  72
  73         if (ddq->d_flags != XFS_DQ_USER &&
  74             ddq->d_flags != XFS_DQ_PROJ &&
  75             ddq->d_flags != XFS_DQ_GROUP)
  76                 return __this_address;
  77
  78         if (id != -1 && id != be32_to_cpu(ddq->d_id))
  79                 return __this_address;
  80
  81         if (!ddq->d_id)
  82                 return NULL;
  83
  84         if (ddq->d_blk_softlimit &&
  85             be64_to_cpu(ddq->d_bcount) > be64_to_cpu(ddq->d_blk_softlimit) &&
  86             !ddq->d_btimer)
  87                 return __this_address;
  88
  89         if (ddq->d_ino_softlimit &&
  90             be64_to_cpu(ddq->d_icount) > be64_to_cpu(ddq->d_ino_softlimit) &&
  91             !ddq->d_itimer)
  92                 return __this_address;
  93
  94         if (ddq->d_rtb_softlimit &&
  95             be64_to_cpu(ddq->d_rtbcount) > be64_to_cpu(ddq->d_rtb_softlimit) &&
  96             !ddq->d_rtbtimer)
  97                 return __this_address;
  98
  99         return NULL;
 100 }
 101
 102 /*
 103  * Do some primitive error checking on ondisk dquot data structures.
 104  */
 105 int
 106 xfs_dquot_repair(
 107         struct xfs_mount        *mp,
 108         struct xfs_disk_dquot   *ddq,
 109         xfs_dqid_t              id,
 110         uint                    type)
 111 {
 112         struct xfs_dqblk        *d = (struct xfs_dqblk *)ddq;
 113
 114
 115         /*
 116          * Typically, a repair is only requested by quotacheck.
 117          */
 118         ASSERT(id != -1);
 119         memset(d, 0, sizeof(xfs_dqblk_t));
 120
 121         d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
 122         d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
 123         d->dd_diskdq.d_flags = type;
 124         d->dd_diskdq.d_id = cpu_to_be32(id);
 125
 126         if (xfs_sb_version_hascrc(&mp->m_sb)) {
 127                 uuid_copy(&d->dd_uuid, &mp->m_sb.sb_meta_uuid);
 128                 xfs_update_cksum((char *)d, sizeof(struct xfs_dqblk),
 129                                  XFS_DQUOT_CRC_OFF);
 130         }
 131
 132         return 0;
 133 }
 134
 135 STATIC bool
 136 xfs_dquot_buf_verify_crc(
 137         struct xfs_mount        *mp,
 138         struct xfs_buf          *bp)
 139 {
 140         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 141         int                     ndquots;
 142         int                     i;
 143
 144         if (!xfs_sb_version_hascrc(&mp->m_sb))
 145                 return true;
 146
 147         /*
 148          * if we are in log recovery, the quota subsystem has not been
 149          * initialised so we have no quotainfo structure. In that case, we need
 150          * to manually calculate the number of dquots in the buffer.
 151          */
 152         if (mp->m_quotainfo)
 153                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 154         else
 155                 ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
 156
 157         for (i = 0; i < ndquots; i++, d++) {
 158                 if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
 159                                  XFS_DQUOT_CRC_OFF))
 160                         return false;
 161                 if (!uuid_equal(&d->dd_uuid, &mp->m_sb.sb_meta_uuid))
 162                         return false;
 163         }
 164         return true;
 165 }
 166
 167 STATIC xfs_failaddr_t
 168 xfs_dquot_buf_verify(
 169         struct xfs_mount        *mp,
 170         struct xfs_buf          *bp)
 171 {
 172         struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
 173         xfs_failaddr_t          fa;
 174         xfs_dqid_t              id = 0;
 175         int                     ndquots;
 176         int                     i;
 177
 178         /*
 179          * if we are in log recovery, the quota subsystem has not been
 180          * initialised so we have no quotainfo structure. In that case, we need
 181          * to manually calculate the number of dquots in the buffer.
 182          */
 183         if (mp->m_quotainfo)
 184                 ndquots = mp->m_quotainfo->qi_dqperchunk;
 185         else
 186                 ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
 187
 188         /*
 189          * On the first read of the buffer, verify that each dquot is valid.
 190          * We don't know what the id of the dquot is supposed to be, just that
 191          * they should be increasing monotonically within the buffer. If the
 192          * first id is corrupt, then it will fail on the second dquot in the
 193          * buffer so corruptions could point to the wrong dquot in this case.
 194          */
 195         for (i = 0; i < ndquots; i++) {
 196                 struct xfs_disk_dquot   *ddq;
 197
 198                 ddq = &d[i].dd_diskdq;
 199
 200                 if (i == 0)
 201                         id = be32_to_cpu(ddq->d_id);
 202
 203                 fa = xfs_dquot_verify(mp, ddq, id + i, 0, 0);
 204                 if (fa)
 205                         return fa;
 206         }
 207
 208         return NULL;
 209 }
 210
 211 static xfs_failaddr_t
 212 xfs_dquot_buf_verify_struct(
 213         struct xfs_buf          *bp)
 214 {
 215         struct xfs_mount        *mp = bp->b_target->bt_mount;
 216
 217         return xfs_dquot_buf_verify(mp, bp);
 218 }
 219
 220 static void
 221 xfs_dquot_buf_read_verify(
 222         struct xfs_buf          *bp)
 223 {
 224         struct xfs_mount        *mp = bp->b_target->bt_mount;
 225         xfs_failaddr_t          fa;
 226
 227         if (!xfs_dquot_buf_verify_crc(mp, bp))
 228                 xfs_verifier_error(bp, -EFSBADCRC, __this_address);
 229         else {
 230                 fa = xfs_dquot_buf_verify(mp, bp);
 231                 if (fa)
 232                         xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
 233         }
 234 }
 235
 236 /*
 237  * readahead errors are silent and simply leave the buffer as !done so a real
 238  * read will then be run with the xfs_dquot_buf_ops verifier. See
 239  * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
 240  * reporting the failure.
 241  */
 242 static void
 243 xfs_dquot_buf_readahead_verify(
 244         struct xfs_buf  *bp)
 245 {
 246         struct xfs_mount        *mp = bp->b_target->bt_mount;
 247
 248         if (!xfs_dquot_buf_verify_crc(mp, bp) ||
 249             xfs_dquot_buf_verify(mp, bp) != NULL) {
 250                 xfs_buf_ioerror(bp, -EIO);
 251                 bp->b_flags &= ~XBF_DONE;
 252         }
 253 }
 254
 255 /*
 256  * we don't calculate the CRC here as that is done when the dquot is flushed to
 257  * the buffer after the update is done. This ensures that the dquot in the
 258  * buffer always has an up-to-date CRC value.
 259  */
 260 static void
 261 xfs_dquot_buf_write_verify(
 262         struct xfs_buf          *bp)
 263 {
 264         struct xfs_mount        *mp = bp->b_target->bt_mount;
 265         xfs_failaddr_t          fa;
 266
 267         fa = xfs_dquot_buf_verify(mp, bp);
 268         if (fa)
 269                 xfs_verifier_error(bp, -EFSCORRUPTED, __this_address);
 270 }
 271
 272 const struct xfs_buf_ops xfs_dquot_buf_ops = {
 273         .name = "xfs_dquot",
 274         .verify_read = xfs_dquot_buf_read_verify,
 275         .verify_write = xfs_dquot_buf_write_verify,
 276         .verify_struct = xfs_dquot_buf_verify_struct,
 277 };
 278
 279 const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
 280         .name = "xfs_dquot_ra",
 281         .verify_read = xfs_dquot_buf_readahead_verify,
 282         .verify_write = xfs_dquot_buf_write_verify,
 283 };